expandable synthetic resinous microspheres are expanded in a matrix by heating under pressure to at least a foaming temperature and permitting the microspheres to expand at a lower pressure.
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6. A method of preparing a heat expandable product, the steps of the method comprising
providing a mixture of heat expandable synthetic resinous microspheres capable of expanding on heating to form monocellular hollow gas-filled spheres within a thermoplastic synthetic resin, heating the mixture to a temperature sufficient to heat plastify the resin under pressure sufficient to prevent expansion of the microspheres, shaping the mixture to a desired configuration, and cooling the mixture below the heat plastifying temperature of the resin.
1. A process for the incorporation of expandable thermoplastic synthetic resinous monocellular microspheres having a thermoplastic resinous shell, a volatile liquid foaming agent therein within a heat plastifiable matrix material which, at its heat plastification temperature does not act as a rapid solvent for the microspheres to cause the destruction thereof by solvent action or heat plastify at a temperature sufficiently high that the microspheres are destroyed by thermal degradation, the steps of the method comprising
admixing the microspheres and matrix forming material, heat plastifying the matrix material and mechanically working the mixture to form a matrix about the microspheres without causing expansion thereof, subsequently passing the mixture into a zone of lower pressure wherein the microspheres expand to form a plurality of hollow, generally monocellular particles within the matrix, and cooling the mixture below the heat plastifying temperature.
2. The method of
3. The method of
4. The method of
5. The method of
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This application is a continuation of our co-pending application Ser. No. 205,289, filed Dec. 6, 1971, now abandoned.
Expandable synthetic resinous microspheres are well known and described in U.S. Pat. No. 3,615,972. Such microspheres are small generally spherical particles having symmetrically encapsulated therein a droplet of a volatile liquid foaming agent. On heating to a temperature sufficient to heat plastify the thermoplastic shell and volatilize the fluid foaming agent, the microspheres expand to form a hollow synthetic resinous shell having a single gas-filled cell therein. Expandable microspheres are particularly desirable for a variety of applications. They can be readily shipped and handled in unexpanded form and find use in a wide variety of applications. Many thermoplastic resinous materials are difficult to foam, for example, polyolefins. In the formation of extruded cellular olefin polymers great care must be exercised in the selection of expanding agents and conditions for the preparation of such a foam.
It would be desirable if there were available an improved method for the expansion of synthetic resinous microspheres in a matrix.
It would also be desirable if there were available an improved method for the incorporation of expandable microspheres within a heat plastifiable matrix.
It would also be desirable if there were available improved synthetic resinous cellular materials.
These benefits and other advantages in accordance with the present invention are achieved in a process for the incorporation of expandable thermoplastic synthetic resinous monocellular microspheres having a thermoplastic resinous shell, a volatile fluid foaming agent therein within a heat plastifiable matrix material, the steps of the method comprising admixing the microspheres and matrix forming material, heat plastifying the matrix material and mechanically working the mixture to form a matrix about the microspheres without causing expansion thereof, subsequently passing the mixture into a zone of lower pressure wherein the microspheres expand to form a plurality of hollow, generally monocellular particles within the matrix and cooling the mixture below the heat plastifying temperature.
Also contemplated within the scope of the present invention is an extruded body comprising a continuous heat plastifiable matrix having therein a plurality of synthetic resinous microspheres, the microspheres being monocellular and having a resin shell having encapsulated therein as a distinct and separate phase a volatile fluid expanding agent.
Another desirable embodiment of the invention is an extruded body comprising a continuous heat plastifiable matrix having dispersed therein a plurality of expanded thermoplastic synthetic resinous gas-containing microspheres.
A wide variety of expandable synthetic resinous thermoplastic microspheres may be employed in the practice of the present invention. Some of such microspheres are set forth in U.S. Pat. No. 3,615,972, herewith incorporated by reference. The expandable microspheres useable in the practice of the present invention may be used in admixture with various matrix materials including synthetic resins, tars, waxes and the like. The only critical requirement for the matrix material is that it be heat plastifiable and at its heat plastification temperature it does not act as a rapid solvent for the microspheres to cause the destruction thereof by solvent action or heat plastify at a temperature sufficiently high that the microspheres are destroyed by thermal degradation. The products of the invention and the process are readily carried out employing a wide variety of processing equipment. An autoclave, beneficially agitated, or similar pressure vessel, can conveniently be employed for heating of the expandable microspheres and matrix forming material. Particularly desirable equipment for the practice of the present invention is a screw extruder which may be of the reciprocating screw type wherein a microsphere-matrix mixture may be processed employing more or less conventional extrusion, or screw injection molding techniques. Surprisingly, the expandable microspheres pass through conventional extrusion equipment without significant destruction thereof. Various synthetic resins beneficially are admixed with expandable microspheres and extruded to provide a foamed product, or alternately, by reducing the temperature of the extrude adjacent the die, the solid resinous matrix is extruded which contains the unexpanded microspheres. Such an unexpanded product may then be heated at a later time to cause expansion at ambient pressure. Beneficially when employing synthetic resinous matrices, it is generally desirable to provide the resin in a finely divided form to facilitate admixture with the microspheres. The finely divided (passing 50 mesh screen US Sieve Size) particulate resin is particularly advantageous when a screw extruder or screw injection molding machine is employed, and neither of these devices provides a high level of mixing of the heat plastified resin within the apparatus. Desirably, when a heat plastifiable matrix is employed for the preparation of the microsphere-containing product, a wide variety of additives may be utilized including dyes, pigments, fillers and plasticizers. Particularly advantageous are glass reinforcing fibers. The proportion of microspheres employed may be varied within wide limits depending on the particular nature of the product desired. Beneficially, as little as about 0.01 weight percent of microspheres can be utilized wherein the end product desirably has a density approximating that of the resin. Beneficially, such a mixture is particularly advantageous for injection molding of articles having thick sections. The presence of a minor amount of expandable microspheres prevents or reduces the tendency of the molded articles to show sink marks. Alternately, useful products are obtained when up to 99 weight percent of the expandable microspheres are employed with the matrix when very low density products are desired. One particularly advantageous embodiment of the invention is expandable granules prepared by extrusion of a synthetic resinous material with unexpanded microspheres to provide a plurality of pellets or beads containing unexpanded microspheres. Such particles can then be molded and formed by conventional steam chest molding procedures which are widely used with expanded polystyrene granules. The use of expandable microspheres provides synthetic resinous foam having a generally uniform small cell size and permits blowing agent retention in cases where such retention would not occur for a desirable length of time without the expandable microspheres, for example, polyolefins such as polyethylene are readily processed by conventional techniques to provide an expandable granule but such granules have a useful life which is much too short for most commercial applications. In contrast, by employing expandable microspheres a molding grade granule is readily prepared which has a shelf life in excess of six months.
The invention is further illustrated but not limited by the following examples.
A plurality of blends of resin and an expandable microsphere having a polymer shell of about 60 percent styrene, 40 weight percent acrylonitrile having encapsulated therein a distinct and separate droplet of isobutane (about 20 percent by weight of the microspheres) and 10 parts by weight of the microspheres are employed with 80 parts by weight of resin and the resulting mixture extruded from a screw extruder under the various conditions set forth in Table I.
TABLE I |
__________________________________________________________________________ |
FOAM COMPOSITION EXTRUSION CONDITIONS |
Wt. |
Wt. % |
Temperatures, ° F. |
Screw |
Die Screen |
Slot |
No FOAM |
SAMPLE NO. |
Polymer Matrix |
% MS1 |
Zone 1 |
Zone 2 |
Die |
Speed2 |
Press3 |
Pak Die |
Die DENSITY4 |
__________________________________________________________________________ |
1 Blend of 90 |
80 10 200 400 350 |
20 900 X 59.1 |
2 weight percent |
↓ |
↓ |
200 350 305 |
20 1000 |
X 38.1 |
3 high density poly- |
↓ |
↓ |
200 300 270 |
20 1200 |
X 26.4* |
3A ethylene with 10 |
↓ |
↓ |
200 300 270 |
20 1200 |
X 38.3 |
4 weight percent |
↓ |
↓ |
200 275 250 |
20 2700 |
X 24.6 |
5 copolymer of about |
↓ |
↓ |
200 275 250 |
25 3500 |
X 19.9 |
6 80 weight percent |
↓285 |
260 20 1200 |
X 24.3 |
7 ethylene with 20 |
↓ |
↓ |
200 280 250 |
20 3200 |
X 21.4 |
8 weight percent |
↓ |
↓ |
200 280 250 |
55 900 X 19.3 |
9 vinyl acetate |
↓ |
↓ |
200 280 250 |
55 0 X 28.5 |
1 Copolymer of |
90 10 200 280 260 |
45 500 X 30.5 |
2 about 80 weight |
↓ |
↓ |
200 265 250 |
60 900 X 19.9 |
3 percent ethylene |
↓ |
↓ |
200 265 250 |
83 900 X 16.7 |
4 with 20 weight |
↓ |
↓ |
200 265 250 |
20 200 X 17.4 |
5 percent vinyl |
↓ |
↓ |
200 265 250 |
60 900 X 23.7 |
acetate ↓ |
↓ |
1 ABS resin 90 10 400 400 350 |
20 200 X 59.6 |
2 commercially |
↓ |
↓ |
210 400 350 |
47 200 X 48.6 |
available as |
↓ |
↓ |
"Tybrene" ↓ |
↓ |
1 Butadiene 90 10 200 300 270 |
20 800 X 19.75 |
2 rubber avail- |
↓ |
↓ |
200 360 285 |
20 200 X 42.2 |
3 able under the |
↓ |
↓ |
200 350 305 |
72 500 X 36.7 |
4 trade designa- |
↓ |
↓ |
200 400 325 |
20 150 X 50.9* |
4A tion of "Tufprene" |
↓ |
↓ |
200 400 325 |
20 150 X 63.75 |
5 ↓ |
↓ |
200 400 325 |
72 500 X 46.4* |
5A ↓ |
↓ |
200 400 325 |
72 500 X 53.6 |
__________________________________________________________________________ |
FOOTNOTES: |
1 = weight percent microspheres |
2 = revolutions per minute |
3 = pounds per square inch gauge |
4 = pounds per cubic foot |
* = water cooled |
The densities of the resultant products are measured. In each case, the product is a uniform, fine-celled foam showing no evidence of rat holes or other significant imperfections.
The product extruded from Run 1 is divided into a plurality of pellets measuring about 1/8 by 1/8 by 1/4 inch and placed in a hollow metal mold which in turn is placed in a circulating air oven having a temperature of about 150°C for a period of about 30 minutes. The mold is subsequently removed from the air oven and cooled to ambient temperature. On opening the mold and removing the contents the particles are found to have foamed to fill the mold and form a unitary reproduction of the internal configuration of the mold.
The procedure of Example 1 is repeated using a mixture of 60 parts by weight of a polyvinyl chloride plastisol grade resin commercially available as "Geon 121", 40 parts by weight of di-(2-ethylhexyl)phthalate and 6 parts by weight of expandable microspheres having a shell of 75 parts by weight vinylidene chloride, 25 parts by weight acrylonitrile and containing about 20 weight percent neopentane. The mixture is extruded at a temperature of about 130°C The product obtained is a fine-celled rubbery foam.
As is apparent from the foregoing specification, the present invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. For this reason, it is to be fully understood that all of the foregoing is intended to be merely illustrative and is not to be construed or interpreted as being restrictive or otherwise limiting of the present invention.
Cohrs, William E., Gunderman, Roland E.
Patent | Priority | Assignee | Title |
10383957, | Jan 06 2015 | JOVIAT, LLC | Near-infrared fluorescent surgical dye markers |
11515659, | Mar 02 2020 | LUXSHARE PRECISION INDUSTRY CO., LTD. | Electronic device with recognizable shell and manufacturing method for the recognizable covering plate |
4255524, | Oct 16 1978 | Institut Francais du Petrole | Syntactic foam compositions useful for manufacturing floating articles |
4351913, | Feb 19 1981 | SIECOR TECHNOLOGY, INC | Filling materials for electrical and light waveguide communications cables |
4430448, | Jun 11 1981 | Elastic molded body comprising a cell structure and process for producing such a molded body | |
4451584, | May 21 1982 | SECANS AG, C O DR BARTH GARTENSTRASSE 2, CH-6300 ZUG SWITZERLAND | Molding compound for molding body portions and process for producing this molding compound |
4451585, | Feb 05 1981 | Kemanord AB | Resin-impregnated fibre composite materials and a process for their manufacture |
4634724, | Aug 31 1984 | ELIOKEM | Crack resistant coating for masonry structures |
4771079, | Jul 18 1985 | Sovereign Holdings, LLC | Graphic art printing media using a syntactic foam based on expanded hollow polymeric microspheres |
5192834, | Mar 15 1989 | Sumitomo Electric Industries, Ltd. | Insulated electric wire |
5205290, | Apr 05 1991 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Low density microspheres and their use as contrast agents for computed tomography |
5281408, | Apr 05 1991 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Low density microspheres and their use as contrast agents for computed tomography |
5429869, | Feb 26 1993 | W. L. Gore & Associates, Inc.; W L GORE & ASSOCIATES, INC | Composition of expanded polytetrafluoroethylene and similar polymers and method for producing same |
5456900, | Apr 05 1991 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Low density microspheres and their use as contrast agents for computed tomography |
5468314, | Feb 26 1993 | W. L. Gore & Associates, Inc. | Process for making an electrical cable with expandable insulation |
5484815, | Jun 23 1988 | Casco Nobel AB | Process for preparation of expanded thermoplastic microspheres |
5520961, | Jun 03 1992 | AKZO NOBEL B V | Plastisol-based coating composition |
5527521, | Apr 05 1991 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Low density microspheres and suspensions and their use as contrast agents for computed tomography and in other applications |
5547656, | Apr 05 1991 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Low density microspheres and their use as contrast agents for computed tomography, and in other applications |
5565154, | Sep 21 1993 | W L GORE & ASSOCIATES, INC | Methods for making puffed insulative material |
5571592, | Sep 21 1993 | W L GORE & ASSOCIATES, INC | Puffed insulative material |
5585119, | Jun 23 1988 | Casco Nobel AB | Device for preparation of expanded thermoplastic microspheres |
5629364, | Nov 14 1994 | Casco Nobel AB | Coating composition |
5733572, | Dec 22 1989 | IMARX THERAPEUTICS, INC | Gas and gaseous precursor filled microspheres as topical and subcutaneous delivery vehicles |
5736121, | May 23 1994 | IMARX THERAPEUTICS, INC | Stabilized homogenous suspensions as computed tomography contrast agents |
5750931, | Feb 26 1993 | W L GORE & ASSOCIATES, INC | Electrical cable with improved insulation and process for making same |
5769080, | Dec 22 1989 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Gas filled liposomes and stabilized gas bubbles and their use as ultrasonic contrast agents |
5770222, | Dec 22 1989 | CEREVAST THERAPEUTICS, INC | Therapeutic drug delivery systems |
5776429, | Dec 22 1989 | LANTHEUS MEDICAL IMAGING, INC | Method of preparing gas-filled microspheres using a lyophilized lipids |
5830430, | Feb 21 1995 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Cationic lipids and the use thereof |
5834526, | Jul 11 1997 | W L GORE & ASSOCIATES, INC | Expandable hollow particles |
5846517, | Sep 11 1996 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Methods for diagnostic imaging using a renal contrast agent and a vasodilator |
5853752, | Dec 22 1989 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Methods of preparing gas and gaseous precursor-filled microspheres |
5874062, | Apr 05 1991 | IMARX THERAPEUTICS, INC | Methods of computed tomography using perfluorocarbon gaseous filled microspheres as contrast agents |
5916671, | Feb 26 1993 | W L GORE & ASSOCIATES, INC | Reusable resilient gasket and method of using same |
5922304, | Dec 22 1989 | CEREVAST MEDICAL, INC | Gaseous precursor filled microspheres as magnetic resonance imaging contrast agents |
5985246, | Dec 22 1989 | LANTHEUS MEDICAL IMAGING, INC | Contrast agents for ultrasonic imaging and methods for preparing the same |
5997898, | Jun 06 1995 | IMARX THERAPEUTICS, INC | Stabilized compositions of fluorinated amphiphiles for methods of therapeutic delivery |
6001335, | Dec 22 1989 | LANTHEUS MEDICAL IMAGING, INC | Contrasting agents for ultrasonic imaging and methods for preparing the same |
6004641, | Jul 11 1997 | LASALLE BANK NATIONAL ASSOCIATION, AS ADMINISTRATIVE AGENT | Molded plastisol article with textured exterior |
6028066, | May 06 1997 | IMARX THERAPEUTICS, INC | Prodrugs comprising fluorinated amphiphiles |
6033645, | Jun 19 1996 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Methods for diagnostic imaging by regulating the administration rate of a contrast agent |
6033646, | Dec 22 1989 | LANTHEUS MEDICAL IMAGING, INC | Method of preparing fluorinated gas microspheres |
6039557, | Dec 22 1989 | LANTHEUS MEDICAL IMAGING, INC | Apparatus for making gas-filled vesicles of optimal size |
6056938, | Feb 21 1995 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Cationic lipids and the use thereof |
6058994, | May 19 1997 | The Yokohama Rubber Co., Ltd. | Rubber composition for tire-tread having high frictional force on ice and pneumatic tire using same |
6071494, | Sep 11 1996 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Methods for diagnostic imaging using a contrast agent and a renal vasodilator |
6071495, | Dec 22 1989 | LANTHEUS MEDICAL IMAGING, INC | Targeted gas and gaseous precursor-filled liposomes |
6088613, | Dec 22 1989 | CEREVAST THERAPEUTICS, INC | Method of magnetic resonance focused surgical and therapeutic ultrasound |
6090800, | May 06 1997 | IMARX THERAPEUTICS, INC | Lipid soluble steroid prodrugs |
6117414, | Apr 05 1991 | IMARX THERAPEUTICS, INC | Method of computed tomography using fluorinated gas-filled lipid microspheres as contract agents |
6120751, | Mar 21 1997 | IMARX THERAPEUTICS, INC | Charged lipids and uses for the same |
6123923, | Dec 18 1997 | CEREVAST THERAPEUTICS, INC | Optoacoustic contrast agents and methods for their use |
6139819, | Jun 07 1995 | CEREVAST MEDICAL, INC | Targeted contrast agents for diagnostic and therapeutic use |
6143276, | Mar 21 1997 | IMARX THERAPEUTICS, INC | Methods for delivering bioactive agents to regions of elevated temperatures |
6146657, | Dec 22 1989 | LANTHEUS MEDICAL IMAGING, INC | Gas-filled lipid spheres for use in diagnostic and therapeutic applications |
6184259, | Sep 16 1997 | Interplastica, S.r.l. | Material containing expandable microspheres and process for the production thereof |
6210788, | Oct 07 1994 | Method for producing a thermoplastic synthetic material and immobilization element provided therewith | |
6231834, | Jun 07 1995 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Methods for ultrasound imaging involving the use of a contrast agent and multiple images and processing of same |
6235801, | Apr 02 1999 | TE Connectivity Corporation | Method of expanding a gel material |
6315981, | Dec 22 1989 | CEREVAST THERAPEUTICS, INC | Gas filled microspheres as magnetic resonance imaging contrast agents |
6403056, | Mar 21 1997 | CEREVAST MEDICAL, INC | Method for delivering bioactive agents using cochleates |
6414139, | Sep 03 1996 | IMARX THERAPEUTICS, INC | Silicon amphiphilic compounds and the use thereof |
6416740, | May 13 1997 | BRISTOL-MYERS SQUIBB MEDICAL IMAGING, INC | Acoustically active drug delivery systems |
6443898, | Dec 22 1989 | CEREVAST MEDICAL, INC | Therapeutic delivery systems |
6444660, | May 06 1997 | CEREVAST THERAPEUTICS, INC | Lipid soluble steroid prodrugs |
6461586, | Dec 22 1989 | CEREVAST THERAPEUTICS, INC | Method of magnetic resonance focused surgical and therapeutic ultrasound |
6479034, | Dec 22 1989 | LANTHEUS MEDICAL IMAGING, INC | Method of preparing gas and gaseous precursor-filled microspheres |
6521211, | Jun 07 1995 | BRISTOL-MYERS SQUIBB MEDICAL IMAGING, INC | Methods of imaging and treatment with targeted compositions |
6524413, | Aug 09 1999 | MB&F MANUFACTURING, LLC, A DELAWARE LIMITED LIABILITY COMPANY | Preservation mat board |
6528039, | Apr 05 1991 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Low density microspheres and their use as contrast agents for computed tomography and in other applications |
6537246, | Jun 18 1997 | CEREVAST THERAPEUTICS, INC | Oxygen delivery agents and uses for the same |
6548047, | Sep 15 1997 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Thermal preactivation of gaseous precursor filled compositions |
6551576, | Dec 22 1989 | LANTHEUS MEDICAL IMAGING, INC | Container with multi-phase composition for use in diagnostic and therapeutic applications |
6576075, | May 31 1994 | Avery Dennison Corporation | Method of making and using a flexographic plate mounting tape |
6576220, | Mar 11 1994 | CEREVAST MEDICAL, INC | Non-invasive methods for surgery in the vasculature |
6582633, | Jan 17 2001 | Akzo Nobel N.V. | Process for producing objects |
6638767, | May 01 1996 | CEREVAST THERAPEUTICS, INC | Methods for delivering compounds into a cell |
6716412, | Sep 15 1997 | CEREVAST MEDICAL, INC | Methods of ultrasound treatment using gas or gaseous precursor-filled compositions |
6743779, | Nov 29 1994 | CEREVAST THERAPEUTICS, INC | Methods for delivering compounds into a cell |
6761843, | Mar 08 2001 | Fujitsu General Limited | Method for manufacturing synthetic resin moldings |
6773696, | Apr 05 1991 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Contrast agent comprising low density microspheres |
6808720, | Mar 21 1997 | CEREVAST THERAPEUTICS, INC | Charged lipids and uses for the same |
6884407, | Sep 11 1996 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Methods for diagnostic imaging involving the use of a contrast agent and a coronary vasodilator |
6894218, | Apr 03 2000 | LANTOR B V | Cable tape and method for manufacturing a cable tape |
6998107, | Apr 05 1991 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Composition comprising low density microspheres |
7078015, | Dec 22 1989 | ImaRx Therapeutics, Inc. | Ultrasound imaging and treatment |
7083572, | Nov 30 1993 | Bristol-Myers Squibb Medical Imaging, Inc. | Therapeutic delivery systems |
7105151, | Jun 18 1997 | CEREVAST THERAPEUTICS, INC | Oxygen delivery agents and uses for the same |
7329402, | Jun 07 1995 | ImaRx Pharmaceutical Corp. | Methods of imaging and treatment |
7344705, | Apr 05 1991 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Composition comprising low density microspheres |
7452551, | Oct 30 2000 | CEREVAST MEDICAL, INC | Targeted compositions for diagnostic and therapeutic use |
7612033, | Nov 29 1994 | CEREVAST THERAPEUTICS, INC | Methods for delivering compounds into a cell |
7780875, | Jan 13 2005 | Cinvention AG | Composite materials containing carbon nanoparticles |
8084056, | Jan 14 1998 | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ASSIGNEE | Preparation of a lipid blend and a phospholipid suspension containing the lipid blend |
8317976, | Jan 26 2000 | International Paper Company | Cut resistant paper and paper articles and method for making same |
8377526, | Mar 11 2005 | International Paper Company | Compositions containing expandable microspheres and an ionic compound, as well as methods of making and using the same |
8382945, | Aug 28 2008 | International Paper Company | Expandable microspheres and methods of making and using the same |
8460512, | Sep 13 2002 | International Paper Company | Paper with improved stiffness and bulk and method for making same |
8536087, | Apr 08 2010 | IIMAK; International Imaging Materials, Inc | Thermographic imaging element |
8658205, | Jan 14 1998 | Lantheus Medical Imaging, Inc. | Preparation of a lipid blend and a phospholipid suspension containing the lipid blend |
8679294, | Aug 28 2008 | International Paper Company | Expandable microspheres and methods of making and using the same |
8685441, | Jan 14 1998 | Lantheus Medical Imaging, Inc. | Preparation of a lipid blend and a phospholipid suspension containing the lipid blend |
8747892, | Jan 14 1998 | Lantheus Medical Imaging, Inc. | Preparation of a lipid blend and a phospholipid suspension containing the lipid blend |
8790494, | Sep 13 2002 | International Paper Company | Paper with improved stiffness and bulk and method for making same |
9545457, | Jan 14 1998 | Lantheus Medical Imaging, Inc. | Preparation of a lipid blend and a phospholipid suspension containing the lipid blend |
9757910, | Apr 02 2012 | TOKAI KOGYO CO , LTD | Injection molded product and method for manufacturing same |
Patent | Priority | Assignee | Title |
3219600, | |||
3353981, | |||
3466353, | |||
3515569, | |||
3615569, | |||
3673126, |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
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